1. Field of the Invention
The present invention relates to a waterproof connector, more particularly to a waterproof connector in which a sealing member is installed to the housing of a connector to prevent water from permeating the connector originating from a connected portion when the connector is connected to another connector.
2. Prior Art
A waterproof connector unit, which consists of a male connector and a female connector, whereby a sealing member is applied between the male and female connectors to prevent water originating from the connected portion from permeating the connector, has been disclosed in Japanese Laid-Open Patent Publication No. 8(1996)-45601.
A waterproof connector unit 40 described in the abovementioned laid-open patent publication is provided with a male housing 41 and a female housing 50, as shown in FIG. 6. The male housing 41 is provided with a tubular portion 42 directed at a connecting side, in which a fitting portion 42a with a large diameter, a step portion 42b and a fitting portion 42c with a small diameter are formed. A locking protrusion 43 directed towards a connecting direction in an approximately perpendicular way is formed on the outside surface of the tube portion 42, with the rear surface of the locking protrusion 43 serving as an engaging surface 43a. A terminal 44 is housed in the male housing 41.
On the other hand, the female housing 50 is provided with an inner tube portion 51 which is fitted into the fitting portion 42c of the male housing 41, and an outer tube portion 52 for inserting the tube portion 42 between the inner tube portion 51 and the outer tube portion 52, while a flange-shaped limiting portion 53 is provided at the base portion of the inner tube portion 51. The inside of the inner tube portion 51 has a terminal housing hole 54, while a locking arm 55 is provided between the inner tube portion 51 and the outer tube portion 52 for engaging with the locking protrusion 43 of the male housing 41. Further, a tubular elastic member 56 for waterproof purposes is fitted around the circumference of the inner tube portion 51.
The male housing 41 and the female housing 50 are connected in such manner that the tubular elastic member 56 is made to fit the inner tube portion 51 of the female housing 50 by means of a flange portion 56b and the male housing 41 is thereafter pushed down to the female housing 50 such that the inner tube portion 51 and the tubular elastic member 56 fit into the fitting portion 42c and the fitting portion 42a, respectively. In this manner, shaking of the connected portion is designed to be eliminated and render it waterproof.
The waterproof connector unit is composed of the male housing 41 and the female housing 50, which includes the outer tube portion 52 of a large diameter and the inner tube portion 51 of a small diameter, with the outer tube portion 52 being concentrically disposed in relation to the inner tube portion 51, and the fitting portion 42 of the male housing 41 being inserted between them, and is locked by a locking arm.
According to this waterproof connector unit, a gap must be provided between the inner tube portion 51 and the outer tube portion 52 for the fitting portion 42 of the male housing 41 and the locking arm, but when such gap becomes relatively wide, the outer shape of the housing becomes significantly deformed. Further, because of the existence of the gap, a part of the tubular elastic member is exposed to the outside, although the tubular elastic member is housed in the outer tube portion 52 of a large diameter. For this reason, dust, dirt or the like easily attaches to the elastic member as to affect its waterproofness when it is connected to the male housing 41. Furthermore, since waterproof means is not applied to the rear surface of the connector housing, particularly the area near the terminal inserting port, there are cases where water permeates or penetrates this area.
Moreover, since the tube portion of the male housing 41 and the outer tube portion of the female housing 50 overlap when the two are connected to each other, this type of waterproof connector unit cannot be made smaller.